NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

TREMONTON prefixes in area code 435

NANPA records 5 assigned NXX blocks to rate center TREMONTON in area code 435, 1.0% of the 501 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 4 holders hold those blocks, the largest being CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT (2), T-MOBILE USA, INC. (1), NEW CINGULAR WIRELESS PCS, LLC (1). The earliest assignment on record here is 2006-12-20 and the most recent 2021-07-16. 3 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

5 assigned blocks – 1% of 435
4 holders of record
3 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
435-207 Frontier CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT – no yes
435-257 Frontier CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT – no yes
435-282 T-Mobile T-MOBILE USA, INC. 2006-12-20 yes yes
435-291 AT&T NEW CINGULAR WIRELESS PCS, LLC 2007-08-23 yes yes
435-732 FRACTEL, LLC 2021-07-16 yes yes

The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.

Who holds the blocks

HolderBrandBlocksShare here
CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT Frontier 2 40%
T-MOBILE USA, INC. T-Mobile 1 20%
NEW CINGULAR WIRELESS PCS, LLC AT&T 1 20%
FRACTEL, LLC – 1 20%

Frequently asked

Which prefixes belong to TREMONTON in area code 435?

5 blocks: 207, 257, 282, 291, 732. The table above gives the holder of each.

Which carriers have numbers in TREMONTON?

CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT (2 blocks), T-MOBILE USA, INC. (1 block), NEW CINGULAR WIRELESS PCS, LLC (1 block), FRACTEL, LLC (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is TREMONTON a city?

It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.

Other rate centers in 435

All 501 prefixes in 435